[ifdotpy]

• Unicode: APFS also folds normalization on case-sensitive volumes. Collision checks (refuse_case_collisions, case_clash, refuse_case_clash, refuse_remaining_clashes, git import) now run there with a normalization key, and refuse before anything is deleted or written.
• Save: APFS decides 'changed' with the status rules (content, type, link target, exec bit, added/removed files) instead of thin metadata. touch, chmod 640 and empty folders make no automatic state.
• Caches: before any snapshot of the working folder, a cache path (machine setting or folder overlay, ignored, not versioned) that is a plain folder becomes a cache again. APFS marks it in place (no copy); btrfs copies with reflinks into a new subvolume; OverlayFS keeps caches by path.
• Tests: t72-save-change-rules, t73-cache-recreated, t74-unicode-names (all fail on the old binary). macOS local: t01 t02 t03 t05 t59 t64 t66 t67 apfs-local apfs-cache-retention apfs-thin pass.